Radiotherapy is also sometimes used to treat benign (non-cancerous) tumours and other conditions, such as thyroid disease and some blood disorders.

Thisinformation focuses mainly on the use of radiotherapy as a treatment for cancer.

Whyit's used

Radiotherapy can be used, alone or in combination with chemotherapy (chemoradiotherapy), to try to cure cancers.

For people with incurable cancers, radiotherapy is a very effective way of controlling symptoms.

Radiotherapy can also be used before surgery to shrink a tumour so it's easier to remove (known as neoadjuvant treatment), or after surgery to destroy small amounts of tumour that may be left (known as adjuvant treatment).

Howit's carried out

Radiotherapy can be given in two different ways from outside the body (external radiotherapy) or inside the body (internal radiotherapy).

External radiotherapy usually involves using a machine called a linear accelerator, which focuses high-energy radiation beams onto the area requiring treatment. External beam radiotherapy is completely painless.

External beam radiotherapy usually involves a series of daily treatments over a number of days or weeks.

Internal radiotherapy can involve placing a small piece of radioactive material temporarily inside the body near the cancerous cells (known as brachytherapy), or the use of a radioactive liquid that's swallowed or injected. The radiation emitted by internal radiotherapy is painless, though the procedure to insert the source can sometimes cause mild discomfort.

The type of radiotherapy you have and the length of treatment depends on the size and type of cancer, and where it is in your body.

These tend to get better within a few days or weeks of treatment finishing.

In rare cases, radiotherapy can cause significant long-term effects. For example, treatment to the genitals or pelvic region can cause permanent infertility.

4 out of every 10 cancer cures include radiotherapy as part of the treatment plan.

However, radiotherapy doesn't cause cancerous tumours to shrink immediately and it can take some time for the beneficial effects to become apparent. These effects depend on the type of cancer you have, other treatments that may be given alongside it (such as chemotherapy or surgery) and how advanced the tumour is when treatment begins.

Does radiotherapy make you radioactive?

External radiotherapy doesn't make you radioactive, as the radiation passes through your body. However, the radiation emitted by internal brachytherapy radioactive implants can be dangerous to other people while the implant is in place.